Field of the Invention
The invention relates to an optical transmission element having at least one optical waveguide which comprises a given polarization-mode dispersion.
In practice, it can occur that some of the optical waveguides in optical transmission elements comprise an impermissibly high dispersion. As a result, in such optical waveguides their bandwidth for communication transmission can be too strictly limited. Particularly when what is known as a monomode fiber is utilized for the respective optical waveguide, its polarization-mode dispersion--that is, the transit time difference between its light waves, or modes, respectively, that are capable of dispersion (=natural waves)--can exceed an allowed limit value. This would lead to an impermissibly high impulse distribution of light signals that are to be transmitted in the respective optical waveguide.
U.S. Pat. No. 5,867,616 (see International PCT publication WO 97/06456) describes an optical waveguide in which, in order to reduce polarization-mode dispersion, imperfections--that is to say, birefringences-in the form of trenches are introduced into a preform of the optical waveguide during production.
International PCT publication WO 96/23739 teaches a method for producing an optical fiber. Manipulations are performed on the fiber by irradiation during the production process--that is to say, during the process of producing the preform from which the fibers are drawn.
U.S. Pat. No. 5,440,659 (see European published patent application EP 0 646 819 A1 teaches a method for producing a fiber-optic cable wherein a plurality of optical fibers are stranded together so as to effectuate a reduction of the polarization-mode dispersion.